Water cooled concentric nozzles for a burner



Sept. 22, 1964 o. ANSCHUTZ ETAL 3,149,613

WATER coouao CONCENTRIC NOZZLES FOR A BURNER Filed Jan. 10, 1962 2Sheets-Sheet 1 P 1964 V o. ANSCH-UTZ ETAL 3,149,613

WATER COOLED CONCENTRIC NOZZLES FOR A- BURNER Filed Jan 10, 1962 2Sheets-Sheet 2 OQOOO 0050 8 't g &

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United States Patent 3,149,613 WATER CQOLED CQNCENTRIC N OZZLES FOR ABURNER Qtto Anschiitz and Franz Rudolph, Gummershach, Rh neland,Germany, assignors to L. & C. Stemmnller G.m.h.H., Gummershach,Rhineland, Germany Filed Jan. ltd, 1962, Ser. No. 165,727 Claimspriority, application Germany Jan. 11, 1961 6 Claims. (Cl. 122-235) Thepresent invention relates to a cooled burner with a cooling systemconnected to a burner circuit.

The invention is characterized primarily in that the cooling pipesincluding their feeding and discharge pipes are fixedly connected to theburner construction so that after disconnection of the connectingconduits the burners together with the cooling system pertaining theretocan be removed and installed as a unit.

In order to avoid a premature destruction of the feeding and dischargepipes by coal dust passing by, these pipes are, according to a furtherdevelopment of the invention, passed through the air passages of theburner. The cooling pipes may be so designed or coiled that they restagainst the inner or outer side of the wall of the air nozzles, or theymay form an extension of said wall and may be directly adjacent to thatend of the wall which faces the fire chamber.

In the first instance, the cooling coils are always mounted on that sideof the wall which is exposed to the air flow. With a burner providedwith a central air nozzle, an annular nozzle of fuel-dust-air mixture,and a surrounding or enveloping air nozzle, the wall confining thecentral air nozzle is cooled by cooling coils resting on the inside ofthe walls which coils are thus exposed to the air fiow in the centralair nozzle, whereas the outer wall confining the fuel-dust-air nozzle ison the outside surrounded by cooling coils, and the outer wall of theenveloping air nozzle has cooling coils on the inside. In this way, thecooling coils are exposed only by contact with the air stream.

In order to reduce the formation of turbulence in the enveloping airnozzle, guiding bafiles are arranged which cover the cooling coils inthe enveloping air nozzle. If desired, the guiding baffles may extend upto the nozzle mouth whereby the coils would be completely surroundedbetween wall and guiding baffle. In the second instance, either thosewalls confining the fiow of air in the enveloping or annular nozzle areextended toward the mouth and thus cover the pipes with regard to thefuel-air nozzle or stream, or the intermediate spaces between the pipewalls are covered by welding thereto wires so that an approximatelyuniform surface will be formed which will reduce the formation ofturbulence on the walls and will thereby prevent the fuel dust particlesfrom attacking the pressure conveying parts.

The feeding and discharge pipe portions are passed partly along thewalls of the central air nozzle and partly along the outer walls of theenveloping air nozzles, and are connected either through flangeconnetion or in a customary manner by welding to the burner coolingcircuit.

FIG. 1 illustrates the employment of the present invention in connectionwith a round burner.

FIG. 2 illustrates the circuit scheme of the cooling coils for threeburners.

FIG. 3 illustrates a modified form of cooling pipe systern.

The burner according to FIG. 1 comprises conduit means including acentral air nozzle, designated with the reference numeral 1, while theannular nozzle through which the fuel-dust-air mixture passes isdesignated with the reference numeral 2, and the enveloping orsurrounding air nozzle is designated with the reference numeral 3. Thearrangement of FIG. 1 furthermore comprises an oil burner 4 which may beemployed as ignition burner or auxiliary burner. Arranged at the mouthof the central air nozzle on the inside of the wall is a cooling pipesystem 5 for cooling the wall between the central air nozzle and theannular passage for the fuel-air mixture. The feeding line 15 leading tothis cooling pipe system is first passed along the Wall of central airnozzle 1 down through coils 5 and thence to discharge through outletpipe 25. The central air nozzle may thus, follow ing the disconnectionof the connecting flanges 40, be installed or removed together with thecooling system pertaining thereto. Within the surrounding air nozzle 3there is arranged a vane ring 24 to give a vortex to the surrounding airstream. The vane ring may be displaced axially by means of a handwheel28 and a lever system 29.

The cooling pipe system 6 for cooling the outer wall of the annularnozzle for the fuel-air mixture is arranged in the enveloping air nozzle3. The feeding pipe 16 for this cooling system is passed along the outerwall of the enveloping air passage and from there outwardly and isconnected to the outer wall. A similar arrangement is employed for thedischarge pipe 26. The cooling pipe system for the outer wall of thefuel-air nozzle is thus supported by the outer wall of the envelopingair passage. A further cooling coil 7 cools the outer wall of theenveloping air passage. In this instance, feeding pipe 17 extendsparallel to the pipe 16 along the outer wall and is then passed towardthe outside. The discharge pipe 27 is, in conformity with thearrangement of FIG. 1, located in front of pipe 2 6. Thus, the coolingpipe system 6 as Well as the cooling pipe system 7, together with theirfeeding and discharge pipes, are supported by the outer wall of theenveloping air passage.

When it is intended to remove the systems, first the connections of thefeeding and discharge pipes are disconnected. Thereupon, the burnerconsisting of all three nozzles can be pulled out as a unit togetherwith all cooling pipe systems. However, there also exists thepossibility of first withdrawing the central air nozzle 1 with thecooling system 5, then pulling out the annular fuel-air nozzle for thefuel-air mixture; and subsequently the annular nozzle. with the guidingplates or baffles, is withdrawn. In both instances, the cooling pipesystem will, after removal of the burner, not remain in the nozzleopening so that those difiiculties which heretofore have beenencountered in connection with the removal and installation of systemsof the general type involved,

Will be avoided.

Each of the three concentric nozzles terminates in a mouth piece.

FIG. 2 shows the circuit scheme of the cooling coils for three burnersI, II and III. The cooling system of burner I comprises the inner coils5a, the middle coils 6a and the outer coils 7a. The corresponding coilsof burner II are 5b, 6b and 7b, and those of burner III 5c, 60 and 7c.15a is the feeding pipe for coils 5a, 16a that for coils 6a and 17a thatfor coils 7a. The discharge pipes are: for coils 5c pipe 25a, for coils60 pipe 26a and for coils 7c pipe 27a.

Coils 7a being connected with coils 6b by line 30, coils 6b with coilsSo by line 31, one cooling fluid stream flows successively through onesystem of outer coils, one system of middle coils and one system ofinner coils.

In the same manner middle coils 6a are connected with inner coils 5b byline 34 and these with outer coils 70 by line 35, while inner coils 5aare connected by line 36 with outer coils 7b and those with middle coils60 by line 38.

In the arrangement shown in FIG. 3, reference numerals 2-2 and 23indicate guide plates mounted before the cooling pipe coils 6 to preventturbulence of the air stream. These guide plates may, as will beunderstood, extend to the end of the coils as shown by referencenumerals 32 and 33 in FIG. 1.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular construction shown in the drawings, butalso comprises any modifications within the scope of the appendedclaims.

What we claim is:

1. In a burner; a central air nozzle, an annular nozzle for a fuel airmixture surrounding said air nozzle, and an enveloping air nozzlesurrounding said annular nozzle, each of said nozzles terminating in amouth piece, said burner having parts thereof fluid cooled, cooling pipemeans including connecting pipes for connection with cooling fluidsupply and discharge pipe lines respectively, said cooling pipe meansincluding said connecting pipes being fixedly connected to therespective adjacent burner parts so as to permit installation andwithdrawal of the burner parts with said cooling pipe means when thelatter are not connected to fluid supply and discharge pipe lines, saidcooling pipe means including coils within the mouth pieces of thenozzles and located within said central nozzle and said envelopingnozzle thereby leaving the annular fuel air nozzle unobstructed, andguiding means covering the said coils at least on the side which isupstream relative to the flow of air in the nozzles.

2. A burner according to claim 1, in which said guiding means extends tothe end of said enveloping air nozzle.

3. In a burner; a central air nozzle, an annular nozzle for a fuel-airmixture surrounding said air nozzle, and an enveloping air nozzlesurrounding said annular nozzle, each of said nozzles terminating in amouth piece, said burner having parts thereof fluid cooled, cooling pipemeans including connecting pipes for connection with cooling fluidsupply and discharge pipe lines respectively, said cooling pipe meansincluding said connecting pipes being fixedly connected to therespective adjacent burner parts so as to permit installation andwithdrawal of the burner parts with said cooling pipe means when thelatter are not connected to fluid supply and discharge pipe lines, saidcooling pipe means including coils within the mouth pieces of thenozzles and located within said central nozzle and said envelopingnozzle thereby leaving the annular fuel air nozzle unobstructed, andguiding means for covering the said coils at least on the side thereofthat is upstream relative to air flow in the nozzles, that portion ofthe said coils which is intended for cooling the outer wall of theannular nozzle being connected to the outer wall of the envelopingnozzle.

4. A burner for a boiler firing system, said burner comprising nozzlemeans including first nozzle means for conducting gas and second nozzlemeans for conducting fuel and surrounding said first nozzle means, saidnozzle means terminating in mouth portions, cooling coils associatedwith the mouth portions of said nozzle means, the cooling coilsassociated with said first nozzle means being located inside the mouthportion of said first nozzle means, and the coils associated with saidsecond nozzle means being located outside the mouth portion of thesecond nozzle means so as to be confined on one side by the secondnozzle means, and guide plates connected to said second nozzle means andbeing disposed over the coolin coils pertaining to the second nozzlemeans.

. 5. A burner for a boiler firing system comprising; inner and outerconcentric nozzle means for air and fuel, respectively, cooling coilsassociated with said nozzle means at the discharge ends thereof, thecooling coils associated with the nozzle means for air being mounted onthe inner wall of said nozzle means and thereby directly confining theair, the cooling coils pertaining to the nozzle means for fuel beingmounted on the outside of the respective nozzle means, and the lastmentioned cooling coils being connected in parallel with the coolingcoils pertaining to the first mentioned nozzle means.

6. A cooling system for a group of fluid cooled burners in which eachburner comprises a plurality of concentric nozzles to be cooled: coolingpipe means arranged adjacent the respective concentric burner nozzles tobe cooled and adapted to convey cooling fluid, the cooling pipe meansfor each said burner nozzle including inlet and outlet means for coolingfluid supply and cooling fluid discharge respectively, said cooling pipemeans also including coil means fixedly connected to the respectiveconcentric burner nozzles in heat exchange relation thereto, the coolingpipe means for the respective nozzles of each individual burner beingarranged in parallel to each other while the outlet means of the coolingpipe means of each nozzle of each burner of the group of burnersconsidered in the direction of the flow of cooling fluid is connected tothe inlet means of the cooling pipe means for different of saidconcentric nozzles of the next succeeding burner, and the inlet means ofthe cooling pipe means of the respective concentric nozzles of the firstburner of the group of burners being connected to a supply of coolingfluid while the outlet means of the cooling pipe means of the respectivenozzles of the last burner of the group of burners are connected todischarge pipe means, whereby the cooling fluid discharged at each ofthe respective outlet means of the cooling pipe means of the nozzles ofthe said last burner will be at about the same temperature.

References Cited in the file of this patent UNITED STATES PATENTS114,739 Wood May 9, 1871 860,983 MacDonald July 23, 1907 1,936,161Hedrick Nov. 21, 1933 2,011,026. Bailey et al. Aug. 13, 1935 2,275,515Dunham Mar. 10, 1942 3,007,458 Leon et al. Nov. 7, 1961

4. A BURNER FOR A BOILER FIRING SYSTEM, SAID BURNER COMPRISING NOZZLEMEANS INCLUDING FIRST NOZZLE MEANS FOR CONDUCTING GAS AND SECOND NOZZLEMEANS FOR CONDUCTING FUEL AND SURROUNDING SAID FIRST NOZZLE MEANS, SAIDNOZZLE MEANS TERMINATING IN MOUTH PORTIONS, COOLING COILS ASSOCIATEDWITH THE MOUTH PORTIONS OF SAID NOZZLE MEANS, THE COOLING COILSASSOCIATED WITH SAID FIRST NOZZLE MEANS BEING LOCATED INSIDE THE MOUTHPORTION OF SAID FIRST NOZZLE MEANS, AND THE COILS ASSOCIATED WITH SAIDSECOND NOZZLE MEANS BEING LOCATED OUTSIDE THE MOUTH PORTION OF THESECOND NOZZLE MEANS SO AS TO BE CONFINED ON ONE SIDE BY THE SECONDNOZZLE MEANS, AND GUIDE PLATES CONNECTED TO SAID SECOND NOZZLE MEANS ANDBEING DISPOSED OVER THE COOLING COILS PERTAINING TO THE SECOND NOZZLEMEANS.